Finding the Fourth Proportional to 9,109.79, 12,572.28 and 5,131.69

Step by Step Solution

1. Step 1: Write the proportion equation
   9,109.79 : 12,572.28 = 5,131.69 : x
2. Step 2: Convert to fraction form
   9,109.79/12,572.28 = 5,131.69/x
3. Step 3: Cross multiply
   9,109.79x = 12,572.28 × 5,131.69
4. Step 4: Simplify right side
   9,109.79x = 64,517,043.55
5. Step 5: Solve for x
   x = 64,517,043.55/9,109.79
6. Step 6: Final answer
   x = 7,082.17